Typewriting machine



Feb. 12, 1935. H. J, HART f 1,990,784

TYPEWRITING MACHINE Filed April 4, 1954 me/whom Mmm/1,46.

Patented Feb. 12, 1935 PATENT OFFICE TYPEWRITING MACHINE Henry Joseph Hart, West Hartford,.Conn., as-l signor to Royal Typewriter Company, Inc., New York, N. Y., a corporation of New York Application April 4, 1934, Serial No. 719,015

9 Claims.

The invention relates to new and useful improvements' in typewriting machines generally although more particularly to means engageable by the type bars in the course of their travel toward the platen and effective to retard the speed of movement of `said bars and thereby reduce to the minimum noise occasioned by the striking function of said bars.

An object vof the invention is to provide a yieldable contact member mounted in position to have a portion thereof engaged andbodily displaced by a type bar just prior to its striking the platen for retarding the speed of movement of said type .bar and reducing to a minimum the noise occasioned by its impact-withA the platen.

In its more detailed nature the invention resides in the provision of a coil spring buffer unit secured at its ends only to the typeI bar segment and having its intermediate portion disposed in the path of travel of the type bars-in a manner permitting the same to be yieldably displaced by impact of the type bars in moving toward the platen for the purpose of slowing up the movement of the type bars and minimizing noise of impact thereof with the platen, the displacement of the buffer unit portion being permitted bynovel arcuate deep groove mounting for the buier unit enabling yieldable displacement' of intermediate portions thereof and longitudinal extension of the unit as a whole upon striking contact thereof by the respective type bars.

In the drawin`g: Figure l is a fragmentary face view illustrating the invention applied to a type bar segment.

Figure 2 is an enlarged vertical cross section taken on the line 2--2 on Figure 1.

Figure 3 is an enlarged detail sectional View illustrating the displacement of a buil'er portion upon type bar impact, the displaced position being shown in dotted lines.

Figure 4 is an enlarged detail section illustrating one end mounting of the buffer unit.

In4 the drawing, 5 designates the usual type bar support or segment which is equipped withv a plurality of variously spaced radial kerrs or slots 6 to accommodate the mounting and movement of.

Vthe usual type bars 7. As is customary in the art, the type bars are pivoted to the segment 5 as indicated at'8 and equipped with the usual type blocks 9. 'I'he usual center guide for the type bars is indicated at 10.

The type bar support or segment 5 is of the usual arcuate shape, the collection of type bar pivots being disposed in an arc of a circle as will be observed by reference to Figure 1 of the drawing. 'I'he segment includes the usual banking ring portion 11 which is concentrically disposed Within the arc of the type bar pivots. In conventional typewriter structures the type bars strike the banking ring just prior to engagement of the type blocks 9 with the platen 21. The metal to metal contact of the type bars and the banking ring and the high speed impact of the type blocks 9 with the platen result in objectionable noise 'which' the present invention seeks to reduceto a'minimum. f

In the practical development of the invention, the front face of the segment 5: is equipped with a V-shaped groove 12 disposed concentrically between the banking ring portion 1l and the arc of the type bar pivots 8. While I have specied that the grooveway 12 is V-shaped, the speciiic shape of said grooveway is immaterial so long as the upper wall 13 thereof extends downwardly and rearwardly from the front face o1y the segment as illustrated in Figures 2 and 3 of the draw- The upper or foremost portion of the wall 13 merges with anA overhanging retainer lip 14, the purpose of which will soon become apparent. 'Ihe grooveway V12 extends through the upper edge oi the segment 5 as illustrated in Figure 1 of the drawing and at each terminus of the grooveway is mounted a bracket member 15, said bracket members being secured as at 16 to the segment. A close-coiled spring buiier 17 is mounted in and conforms to the arcuate shape of the grooveway 12 and is screw secured at its ends as at 18 to the bracket members 15. Secured at its ends alone the spring builer unit 17 is normally held against the retaining lip 14 with the forwardly presented portions of the coils its end mountings 18 are disposed in the path of travel of the respective type bars toward the platen and because of the resiliency of the spring and its quality of permitting elongation intermediately oi its iixedly secured ends the intermediate portions o! said unit are free to yield to impact oi said type bars. As each type bar is moved toward platen impact it iirst engages the butler 'spring unit 17 and has its speed of movement retarded thereby for the purpose o! reducing to a'minimum the noise occasioned by type bar, type block impact. The portion of the buffer spring unit 1'7 engaged by a particular type bar is bodily displaced thereby and caused to move down the grooveway wall 13 as indicated in dotted lines in Figure 3 of the drawing. Because of the relation of the rigid end ring mountings of the unit and the downwardly and rearwardly sloping wall 13, the displacement of the unit portion is attended by an elongation or stretching of the unit as a whole which serves to absorb the shock of impact of the type bar and also to materially reduce the speed of movement of said type bar.

After contact with the spring buffer unit 17 the type bars, having had the speed of their movement materially reduced, strike the banking ring portion 11 and thereafter, in the usual manner, the type blocks 9 engage the platen. Thus it vwill be seen that by engagement of the type bars with the yieldable, bodily displaceable spring unit portions, noise of impact of the type barswith the banking ring portion and also that of the type blocks 9 with the platen are reduced to a. minimum. After each displacement of a buffer unit portion by type bar contact and the resultant elongation of the unit occasioned thereby the displaced portion naturally springs back to normal position with the result that the type bar, after completing its impact with the platen, is speeded on its return to normal position. If desired a retaining pin or lug 20 may be positioned at the lower portion of the spring unit receiving grooveway 12 to prevent inadvertent displacement of said unit out of its receiving groove.

I claim:-

1. In a typewriter, the combination of a platen, a. set of type bars movable into engagement with the platen, and a yieldable element supported in the path of movement of the type bars toward the platen and capable of slight elongation whereby intermediate portions thereof are bodily displaced upon impact thereof by saidtype bars for retarding the speed of movement of said type bars. i

2. In a typewriter, the combination of a platen, a set of type bars movable into engagement with the platen, and an elongated buffer unit secured at its-ends only and having acoiled spring body portion located in the path of movement of the type bars towardV the platen whereby intermediate portions of said unit are free to yield bodily to .type bar engagement.

3. In a typewriter, the combination of a platen, a set of type bar s movable into engagement with the platen, a coiled spring bufferunit ,secured at its ends only and located in the path of movement of the vtype bars toward the platen whereby intermediate portions of said unit are free to yield bodily to type bar engagement, and means providing a grooveway to receive said unit and including a wall portion cooperating with the end mountings of said unit' to cause the unit to be slightly elongated when a portion thereof is bodily displaced.

4. In a typewriter, the combination of a platen, a set of type bars pivotally supported with their pivots collectively disposed in an arc of a circle, and a yieldable element disposed in the form of an arc in the path of movement of the type bars toward the platen and `capable of slight elongation whereby intermediate portions thereof are bodily displaced upon impact thereof by said type bars for retarding the speed of 'movement of said type bars. v

5. In a typewriter, the combination of a platen, a set of type bars pivotally supported with their pivots collectively disposed in an arc of a circle, and an elongated buffer unit having a coiled spring body portion disposed in an arc of acircle in the path of movement of the type bars toward the platen and secured at its ends only whereby intermediate portions of said unit are free to yield bodily to type bar engagements.

6. In a typewriter, the combination of a platen, a set of type bars pivotally supported with their pivots collectively disposed in an arc of a circle, a coiled spring buifer unit disposed in an arc of a circle in the path of movement of the type bars toward theplaten and lsecured at its ends only whereby intermediate portions of said unit are free to yield bodily tol type bar engagements, and means providing a grooveway to receive said unit and including a wall portion cooperating with the end' mountings. of said lunit to cause the unit to be slightly elongated when a portion thereof is bodily displaced.

7. In a typewriter, the combination of a platen, a set of type bars movable into engagement with the platen, a coiled spring buffer unit secured at its ends only and located in the path of movement of the type bars toward the platen whereby intermediate portions of said unit are free to yield bodily to type bar engagement, and means providing a V-shaped grooveway including an overhanging lip against which the unit normally rests and a wall portion over which portions of said unit are forced when yielding to type bar concentrically within the arc of type bar pivots and in the path of movement of the type bars toward the platen and secured at its ends only whereby intermediate portions of said unit are free to yield bodily to type bar engagements, and means providing a V-shaped grooveway including an overhanging lip against which the unit normally rests and a wall portion over which portions of said unit are forced when yielding to vtype bar impact and which is vshaped to cooperate with the unit end mountings to cause the unit to be slightly elongated while yielding bodilyr to type bar impacts.

9. In a typewriter, the combination of a platen, a set-of type bars movable into engagement with the platen, a yieldable element supported in the path of movement of the type bars toward the platen and capable' of slight elongation, supports ment to vbe slightly elongated when a portionl thereof is bodily displaced.

HENRY JOSEPH HART. 

